In the Zone

Featured on

January 18, 2011

Atafu Atoll, a small coral island in the South Pacific, demonstrates that Earth is firmly in the middle of the Sun's habitable zone -- the distance from the Sun where temperatures are just right for liquid water. Scientists are looking for planets in the habitable zones of other star systems, which are considered the most likely home for Earth-like life. This image was shot by an astronaut aboard the International Space Station. [NASA]